NASA Announces Discovery of Assault by a Black Hole

Dec.
18, 2007: A powerful jet from a supermassive black
hole is blasting a nearby galaxy, according to new data from
NASA observatories. This never-before witnessed galactic violence
may have a profound effect on planets in the jet's path and
trigger a burst of star birth in its destructive wake.

This
real-life scene, worthy of the most outlandish science fiction,
is playing out in a faraway binary galaxy system known as
3C321. Two galaxies are in orbit around one another. A supermassive
black hole at the core of the system's larger galaxy is spewing
a jet in the direction of its smaller companion.

Above:
A composite image of 3C321. Scroll down the page to see an
artist's illustration labeling the galaxies and the jet. [more]

"We've
seen many jets produced by black holes, but this is the first
time we've seen one punch into another galaxy," says
Dan Evans, a scientist at the Harvard-Smithsonian Center for
Astrophysics and leader of the study. "This jet could
be causing all sorts of problems for the smaller galaxy it
is pummeling."

Jets
from super massive black holes produce large amounts of radiation,
especially high-energy X-rays and gamma-rays, which can be
lethal in large quantities. The combined effects of this radiation
and particles traveling at almost the speed of light could
severely damage the atmospheres of planets lying in the path
of the jet. For example, protective layers of ozone in the
upper atmosphere of planets could be destroyed.

Above:
An artist's illustration of 3C321 with galaxies and jets labeled.
[more]

The
effect of the jet on the companion galaxy is likely to be
substantial, because the galaxies in 3C321 are extremely close
at a distance of only about 20,000 light years apart. They
lie approximately the same distance as Earth is from the center
of the Milky Way galaxy.

The
jet and galactic assault were discovered through the combined
efforts of both space and ground-based telescopes. NASA's
Chandra X-ray Observatory, Hubble Space Telescope, and Spitzer
Space Telescope were part of the effort. Two sophisticated
radio telescopes--the Very Large Array (VLA) in Socorro, New
Mexico, and the Multi-Element Radio Linked Interferometer
Network (MERLIN) in the United Kingdom--were also needed for
the finding.

A
bright spot in the VLA and MERLIN images shows where the jet
has struck the side of the galaxy, dissipating some of the
jet's energy. The collision disrupted and deflected the jet.

A
unique aspect of the discovery in 3C321 is how relatively
short-lived this event is on a cosmic time scale. Features
seen in the VLA and Chandra images indicate that the jet began
impacting the galaxy about one million years ago, a small
fraction of the system's lifetime.

It's
possible that the event is not all bad news for the beleaguered
galaxy. The massive influx of energy and radiation from the
jet could spark the formation of large numbers of stars and
planets after its initial wake of destruction is complete.
In the distant future, say researchers, whole new star systems
may have the lethal jet to thank for their very existance.

The
results from Evans and his colleagues will appear in
the Astrophysical Journal. NASA's Marshall Space Flight
Center, Huntsville, Ala., manages the Chandra program
for the agency's Science Mission Directorate. The Smithsonian
Astrophysical Observatory controls science and flight
operations from the Chandra X-ray Center in Cambridge,
Mass.